In European folklore and folk-belief of the Medieval and Early Modern periods, familiar spirits (sometimes referred to simply as "familiars" or "animal guides") were believed to be supernatural entities that would assist witches and cunning folk in their practice of magic. According to the records of the time, they would appear in numerous guises, often as an animal, but also at times as a human or humanoid figure, and were described as "clearly defined, three-dimensional… forms, vivid with colour and animated with movement and sound" by those alleging to have come into contact with them, unlike later descriptions of ghosts with their "smoky, undefined form[s]".
One thing to note is that you should set up a cache_store that works for you. The default store is disk storage, which might slow down accesses if you put lots of objects in your cache. Disk storage is slow to access, anyway.
But stripping away the irrelevancies gives you a little conceptual nugget; then you just step to the next one, which is closely related. It turns out that the next nugget you've stepped to takes you to some other domain - after you put back all the irrelevancies.